Epilepsy affects three million Americans and fifty million people worldwide. Drug resistant epilepsy (DRE) affects over one third of all people with epilepsy, and may lead to unemployment, injury, and death. Trigeminal Nerve Stimulation (TNS) is an emerging neuromodulation therapy for DRE, which has unique advantages over other techniques. TNS can be delivered bilaterally, at high frequencies, and externally or subcutaneously with excellent safety and efficacy. Unique to TNS is the ability to identify responders with external TNS (eTNS) prior to implantation with a permanent subcutaneous system (sTNS). We have recently completed the first-ever randomized control trial (RCT) of external TNS (eTNS) in 50 subjects with DRE. Forty percent (40.5 percent) experienced greater than 50 percent reduction in seizure frequency at 18 weeks, with significant improvements in mood (Beck Depression Inventory). This human clinical trial provides strong evidence for proof of concept of TNS in DRE. The purpose of this SBIR translational research project is to develop an implantable subcutaneous Trigeminal Nerve Stimulation System (sTNSTM) for the treatment of DRE. This project builds upon NeuroSigma's experience in external Trigeminal Nerve System (eTNSTM) for which it was awarded an STTR in 2011. This SBIR brings together a unique team of biomedical engineers, neuroscientists and neurosurgeons with seminal experience in the development of Trigeminal Nerve Stimulation. Furthermore, we plan to collaborate with Stellar Technologies, a leading manufacturer of intracranial electrodes, and CCC, a respected manufacturer of implantable pulse generators and components since 1969, who has agreed to modify an existing multichannel IPG which meets NeuroSigma's unique design specifications for sTNS.